Trait RosMessage

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pub trait RosMessage:
    Sized
    + Serialize
    + Deserialize {
    const TYPE_NAME: &'static str;
    const TYPE_HASH: &'static str;
    const SERIALIZATION_FORMAT_ID: SerializationFormatId = nros_serdes::format::SerializationFormatId::Cdr;
    const STAMP_OFFSET: Option<usize> = None;
    const MAX_SERIALIZED_BOUND: Option<usize> = None;
}

Expand description

Trait for ROS message types

Identifies a ROS message type by its DDS type name and RIHS hash. All message types implement Serialize and Deserialize.

Required Associated Constants§

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const TYPE_NAME: &'static str

Full ROS type name in DDS format

Example: "std_msgs::msg::dds_::String_"

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const TYPE_HASH: &'static str

RIHS (ROS Interface Hashing Standard) type hash

Used for type validation between publishers and subscribers. Format: 64-character hex string (SHA-256)

Provided Associated Constants§

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const SERIALIZATION_FORMAT_ID: SerializationFormatId = nros_serdes::format::SerializationFormatId::Cdr

RFC-0088 — the serialization format this message’s bytes are in.

Defaulted, on purpose. A required associated type here would force a line onto every hand-written message in every user crate, which is the decision phase-380 W4 already made and reverted once: tightening the message contract to serve a build assertion broke examples/linux/rust/custom-msg, the documented hand-written-message pattern. A defaulted const costs existing implementors nothing and still answers at compile time, which is all the assertion needs.

It lives on RosMessage rather than nros_serdes::schema::Message because only this trait is universal: MessageForRmw requires a schema only under cfg(rmw_needs_type_descriptors) (Cyclone), so a check keyed on the schema would be absent under zenoh and XRCE — and absent under uORB, which is the one backend the check exists for.

Codegen emits an override only for a non-CDR format.

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const STAMP_OFFSET: Option<usize> = None

RFC-0052 / phase-296 W3a — byte offset of header.stamp.sec within this type’s serialized CDR payload (encapsulation header included), or None when the type has no leading std_msgs/Header / builtin_interfaces/Time. Codegen-const, never runtime introspection: CDR here is little-endian with a 4-byte encapsulation header and Time { i32 sec; u32 nanosec } is 4-byte aligned, so a Header-leading (or Time-leading) type carries sec at byte 4 and nanosec at byte 8. On-target max_age monitors peek these two words from the raw receive buffer before deserialization.

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const MAX_SERIALIZED_BOUND: Option<usize> = None

Issue 1179 / phase-498 W3 – the largest serialized size of this type, over XCDR1 and XCDR2, or None when no bound exists (an unbounded member) or nobody stated one.

Codegen emits nros_serdes::size::max_serialized_bound::<Self>(), the same const fn over the schema in the same generated file. It is computed, never a copied number, so it cannot drift from the schema.

It lives HERE, not only on nros_serdes::schema::Message, for the reason SERIALIZATION_FORMAT_ID does: RosMessage is the one universal trait. MessageForRmw requires a schema only on a backend declaring type-descriptors (Cyclone), so on zenoh and XRCE a registration site could not read the bound, and every default receive buffer there took the image-wide size whatever its type. Defaulted, so a hand-written message (examples/linux/rust/custom-msg) still compiles and keeps exactly that default; it may state its own bound by overriding this.

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Trait RosMessage Copy item path

Required Associated Constants§

const TYPE_NAME: &'static str

const TYPE_HASH: &'static str

Provided Associated Constants§

const SERIALIZATION_FORMAT_ID: SerializationFormatId = nros_serdes::format::SerializationFormatId::Cdr

const STAMP_OFFSET: Option<usize> = None

const MAX_SERIALIZED_BOUND: Option<usize> = None

Dyn Compatibility§

Implementations on Foreign Types§

impl RosMessage for AddDiagnosticsRequest

const TYPE_NAME: &'static str = "diagnostic_msgs::srv::dds_::AddDiagnostics_Request_"

const TYPE_HASH: &'static str = "TypeHashNotSupported"

const MAX_SERIALIZED_BOUND: Option<usize>

impl RosMessage for AddDiagnosticsResponse

const TYPE_NAME: &'static str = "diagnostic_msgs::srv::dds_::AddDiagnostics_Response_"

const TYPE_HASH: &'static str = "TypeHashNotSupported"

const MAX_SERIALIZED_BOUND: Option<usize>

impl RosMessage for Bool

const TYPE_NAME: &'static str = "std_msgs::msg::dds_::Bool_"

const TYPE_HASH: &'static str = "TypeHashNotSupported"

const MAX_SERIALIZED_BOUND: Option<usize>

impl RosMessage for Byte

const TYPE_NAME: &'static str = "std_msgs::msg::dds_::Byte_"

const TYPE_HASH: &'static str = "TypeHashNotSupported"

const MAX_SERIALIZED_BOUND: Option<usize>

impl RosMessage for ByteMultiArray

const TYPE_NAME: &'static str = "std_msgs::msg::dds_::ByteMultiArray_"

const TYPE_HASH: &'static str = "TypeHashNotSupported"

const MAX_SERIALIZED_BOUND: Option<usize>

impl RosMessage for Char

const TYPE_NAME: &'static str = "std_msgs::msg::dds_::Char_"

const TYPE_HASH: &'static str = "TypeHashNotSupported"

const MAX_SERIALIZED_BOUND: Option<usize>

impl RosMessage for ColorRGBA

const TYPE_NAME: &'static str = "std_msgs::msg::dds_::ColorRGBA_"

const TYPE_HASH: &'static str = "TypeHashNotSupported"

const MAX_SERIALIZED_BOUND: Option<usize>

impl RosMessage for DiagnosticArray

const TYPE_NAME: &'static str = "diagnostic_msgs::msg::dds_::DiagnosticArray_"

const TYPE_HASH: &'static str = "TypeHashNotSupported"

const STAMP_OFFSET: Option<usize>

const MAX_SERIALIZED_BOUND: Option<usize>

impl RosMessage for DiagnosticStatus

const TYPE_NAME: &'static str = "diagnostic_msgs::msg::dds_::DiagnosticStatus_"

const TYPE_HASH: &'static str = "TypeHashNotSupported"

const MAX_SERIALIZED_BOUND: Option<usize>

impl RosMessage for Duration

const TYPE_NAME: &'static str = "builtin_interfaces::msg::dds_::Duration_"

const TYPE_HASH: &'static str = "TypeHashNotSupported"

const MAX_SERIALIZED_BOUND: Option<usize>

impl RosMessage for Empty

const TYPE_NAME: &'static str = "std_msgs::msg::dds_::Empty_"

const TYPE_HASH: &'static str = "TypeHashNotSupported"

const MAX_SERIALIZED_BOUND: Option<usize>

impl RosMessage for Float32

const TYPE_NAME: &'static str = "std_msgs::msg::dds_::Float32_"

const TYPE_HASH: &'static str = "TypeHashNotSupported"

const MAX_SERIALIZED_BOUND: Option<usize>

impl RosMessage for Float64

const TYPE_NAME: &'static str = "std_msgs::msg::dds_::Float64_"

const TYPE_HASH: &'static str = "TypeHashNotSupported"

const MAX_SERIALIZED_BOUND: Option<usize>

impl RosMessage for Float32MultiArray

const TYPE_NAME: &'static str = "std_msgs::msg::dds_::Float32MultiArray_"

const TYPE_HASH: &'static str = "TypeHashNotSupported"

const MAX_SERIALIZED_BOUND: Option<usize>

impl RosMessage for Float64MultiArray

const TYPE_NAME: &'static str = "std_msgs::msg::dds_::Float64MultiArray_"

const TYPE_HASH: &'static str = "TypeHashNotSupported"

const MAX_SERIALIZED_BOUND: Option<usize>

impl RosMessage for Header

const TYPE_NAME: &'static str = "std_msgs::msg::dds_::Header_"

const TYPE_HASH: &'static str = "TypeHashNotSupported"

const STAMP_OFFSET: Option<usize>

const MAX_SERIALIZED_BOUND: Option<usize>

impl RosMessage for Int8

const TYPE_NAME: &'static str = "std_msgs::msg::dds_::Int8_"

const TYPE_HASH: &'static str = "TypeHashNotSupported"

const MAX_SERIALIZED_BOUND: Option<usize>

Trait RosMessage